The sanctions are part of a crackdown on smuggling of North Korean commodities in violation of UN sanctions resolutions.

The UN Security Council has blacklisted 27 ships, 21 companies and a businessman for helping North Korea breach sanctions, as the United States keeps up pressure on Pyongyang despite its recent overtures towards talks.

The sanctions were passed on a request from the US and they are part of a global crackdown on the smuggling of North Korean commodities in violation of UN sanctions resolutions, which were adopted in response to Pyongyang's nuclear and ballistic missile tests.

The sanctions designations were approved as the US moves to open talks with North Korea on its nuclear drive, with a summit possible between President Donald Trump and Kim Jong-un by the end of May.

Despite the diplomatic opening, the US has made clear they will keep the pressure on Pyongyang to shift course by pressing on with sanctions.

Nikki Haley, the US ambassador to the UN, welcomed the "historic" sanctions package," calling it "a clear sign that the international community is united in our efforts to keep up maximum pressure on the North Korean regime."

"We want to thank the members of the Security Council, as well as Japan and South Korea, for working with us to keep up the pressure and for their commitment to implementing UN Security Council resolutions and holding violators accountable," Haley added on Friday.

Twenty-one shipping and trading firms were hit by an assets freeze. Three of them are based in Hong Kong including Huaxin Shipping, which delivered shipments of North Korean coal to Vietnam in October.

Twelve North Korean firms were blacklisted for running ships involved in illegal transfers of oil and fuel, according to the document.

Two other companies, Shanghai Dongfeng Shipping and Weihai World Shipping Freight, also based in China, were blacklisted for carrying North Korean coal on their vessels.

The remaining firms are in based Singapore, Samoa, the Marshall Islands and Panama.

Businessman sanctioned

A businessman identified as Tsang Yung Yuan was hit by a global travel ban and assets freeze for organising illegal shipments of North Korean coal with a North Korean broker in Russia.

Last year, the Security Council adopted a series of resolutions to ban North Korean exports of commodities in a bid to cut off revenue to the nuclear-armed state's military programmes.

The measures severely restrict deliveries of oil and refined petroleum products to North Korea, but sanctions monitors have reported that Pyongyang has used vessels to dodge those restrictions.

North Korea earned $200m in revenue last year from exports of coal, iron, steel and other banned commodities, according to a recent report.

Only eight North Korean vessels had so far been banned from ports for sanctions-busting - so the inclusion of 13 other ships on Friday was expected to significantly cripple North Korea's maritime network.